Ankle Anatomy PDF

Ankle & Foot Ankle & Foot Functions Stability: Sustain large WB forces Bipedal stance Provide stable BOS Rigid lever for effective push-off during gait Mobility Locomotion Shock absorption Pliable – Foot conforms to terrain Osteology: Basic Terms & Concepts Ankle – whi...

Ankle & Foot Ankle & Foot Functions Stability: Sustain large WB forces Bipedal stance Provide stable BOS Rigid lever for effective push-off during gait Mobility Locomotion Shock absorption Pliable – Foot conforms to terrain Osteology: Basic Terms & Concepts Ankle – which part(s)? Foot – which part(s)? Osteology: Functional Units Medial column Lateral column Talus Calcaneus Navicular Cuboid 3 cuneiforms 4th & 5th metatarsals First 3 metatarsals  Ankle & Foot Movements Fundamental movements: Inversion/eversion: __________ plane & _________ axis DF/PF: __________ plane & _________ axis Abduction/Adduction: __________ plane & _________ axis Ankle & Foot Movements Applied movements: Most movements occur about oblique axes of rotation and cut through each of the 3 cardinal planes Pronation Supination DF PF Abduction Adduction Eversion Inversion  Proximal & Distal Tibiofibular Joints Joints associated with the ankle (talocrural joint) Ankle mortise must be stable and adjustable Proximal & distal tibiofibular joints permit and control changes in the mortise  Proximal Tibiofibular Joint Plane synovial Posterolateral asp of lateral condyle of tibia à fibular head Anatomically distinct from the knee Very little gliding motion occurs at this joint à forces within biceps femoris and LCL are transferred effectively  Distal Tibiofibular Joint Syndesmosis Convex facet of distal fibula à concave fibular notch of tibia No joint capsule Relatively little movement is permitted at this joint Ligaments maintain the stable mortise of the ankle  Proximal & Distal Tibiofibular Joints Periarticular Connective Tissues Provide stability for the ankle mortise Interosseous membrane Supports both proximal & distal joints Binds bones together Attachment for deep ant & post muscles of the leg Interosseous ligament Primary stabilizer of distal tib-fib joint Anterior & posterior tibiofibular ligaments Ankle: Talocrural Joint Articular structures Proximal Rectangular cavity formed by the distal end of tibia and both malleoli Distal Trochlear surface and sides of the talus Trochlea: wedge-shaped dome Anterior wider than posterior Ankle: Talocrural Joint Mortise  Ankle: Talocrural Joint Periarticular Connective Tissues Capsule reinforced by collateral ligaments Medial collateral ligament (MCL) AKA Deltoid ligament Large, triangular fan-shaped Fibers Tibionavicular Tibiocalcaneal Tibiotalar MCL sprain uncommon Ligament very strong & lat malleolus blocking excessive eversion  Ankle: Talocrural Joint Periarticular Connective Tissues Lateral collateral ligaments (LCL) – more often injured than MCL. Why? Anterior talofibular ligament Calcaneofibular ligament Posterior talofibular ligament  Ankle: Talocrural Joint Osteokinematics One degree of freedom Oblique axis of rotation through body of talus & tips of both malleoli Frontal plane à 10 degrees deviated from ML axis Horizontal plane à 6 degrees deviated from ML axis Video from: https://www.youtube.com/watch?v=0R4zRSE_-40 (Time: 0:51 to 1:01; muted)  Ankle: Talocrural Joint Osteokinematics Video from https://www.youtube.com/watch?v=0R4zRSE_-40 (Time 0:31 to 1:44) Ignore the inconsistency between the degree deviations of the axis of rotation stated in this clip and in the last slide  Ankle: Talocrural Joint Osteokinematics Dorsiflexion (main component) asso. with slight abduction & eversion à Pronation Plantarflexion (main component) asso. with slight adduction & inversion à Supination  Ankle: Talocrural Joint Osteokinematics Normal ROM Dorsiflexion: 15 to 25 degrees Plantarflexion: 40 to 55 degrees Functional ROM Gait: 10 degrees DF & 20 degrees PF Running: 20 degrees DF & 30 degrees PF Stair descent: 21 to 36 degrees DF Ankle: Talocrural Joint Arthrokinematcis OKC (unloaded) Dorsiflexion Foot is free to rotate Convex talar dome Rolls anteriorly Slides posteriorly Any lig taut on posterior translation of talus à taut during DF Deltoid lig (tibiotalar fibers) Calcaneofibular lig Posterior talofibular lig Video from: https://www.youtube.com/watch?v=GLoVFtVFR54 Ankle: Talocrural Joint Arthrokinematcis When a patient has limited ankle dorsiflexion range due to reduced accessory motion at the talocrural joint, how can we help the patient increase the dorsiflexion range using joint mobilization? Not a multiple-choice question. Enter your answer. When poll is active, respond at PollEV.com/wingfu738 OR text WINGFU738 to 22333 once to join  Ankle: Talocrural Joint Arthrokinematcis OKC (unloaded) Plantarflexion Foot is free to rotate Convex talar dome Rolls posteriorly Slides anteriorly Any lig taut on anterior translation of talus à taut during PF Deltoid lig (tibionavicular fibers) Anterior talofibular lig Video from: https://www.youtube.com/watch?v=GLoVFtVFR54 Common Terminology Associated with the Subdivisions of Gait Cycle Figure 15.11 in your textbook Common Terminology Associated with the Subdivisions of Gait Cycle Figure 15.12 in your textbook  Ankle: Talocrural Joint Progressive stabilization during stance phase Within the stance phase: From “foot flat” to just after “heel off” Leg rotating forward over the fixed (grounded) foot Ankle dorsiflexing or plantarflexing? Video from: https://www.youtube.com/watch?v=5j4YRHf6Iyo (Time 2:12 to 2:19) Watch the right ankle. Muted on purpose. Ankle: Talocrural Joint Progressive stabilization during stance phase CKC (loaded) Dorsiflexion Leg rotates over the fixed (grounded) foot Roll and slide What bone(s) on what bone(s)? What direction for the roll and what direction for the slide? Ankle: Talocrural Joint Progressive stabilization during stance phase CKC (loaded) Dorsiflexion The wider anterior talus wedges into the mortise à Distal tibia & fibula spread apart slightly Increasing Tauter tibiofibular lig & interosseous ankle membrane stability Increased tension in many collateral ligaments and PF muscles Does it make sense to have more ankle stability during this phase of gait? Tension in distal tibiofibular lig & interosseous membrane à Slight superior translation of fibula at max DF  Subtalar Joint (STJ) Osteokinematics Uni-axial hinge 1 degree of freedom Oblique axis of rotation: pierces the lateral-posterior heel & courses through the STJ in ant, med and sup directions Video from: https://www.youtube.com/watch?v=0R4zRSE_-40 (Time: 4:06 to 4:19; muted) Subtalar Joint (STJ) Osteokinematics DF & PF motions: small; usually ignored clinically; minor components Main components of supination at STJ: Inversion & adduction Main components of pronation at STJ: Eversion & abduction Subtalar Joint Osteokinematics: NWB (OKC) Calcaneus moving on a relatively fixed talus Minor component: Minor component: Slight plantarflexion Slight dorsiflexion  Subtalar Joint Osteokinematics: NWB (OKC) From: https://www.youtube.com/watch?v=0R4zRSE_-40 (Time: 5:28 – 5:41) This clip covers the subtalar joint motions in all three planes and does not differentiate between main and minor components, like those in the last slide. Subtalar Joint Osteokinematics: WB (CKC) Calcaneus fixed to the ground Relative immobile due to load of body weight Only free to move around the AP axis WB calcaneus contributes to inv/ev component of STJ motion Talus contributes to the other 2 coupled components of STJ motion Abd/add DF/PF Subtalar Joint Osteokinematics: WB (CKC) Anterior View of Right Talus (T) and Calcaneus (C) T T C C C T Supinated Neutral Pronated Subtalar Joint Osteokinematics: WB (CKC) Supination and Pronation in Action Video from: https://www.youtube.com/watch?v=7SK_O-NuFr4 (Time: 0:22 to 1:23; muted) Subtalar Joint Osteokinematics: WB (CKC) Significance of Supination and Pronation at STJ Supination: locking of the foot Pronation: Unlocking of the foot Video from: https://www.youtube.com/watch?v=9oy36KEQF7s (Time: 0:59 to 1:12; muted) Subtalar Joint Osteokinematics: WB (CKC) Supination (locking of the foot) Calcaneal inversion (varus) Talar abduction Externally rotating talus coupled with ER of tibia & fibular (ankle mortise) Talar dorsiflexion Posterior/superior translation Elevation of medial longitudinal arch (MLA) *Ignore the midfoot & forefoot motion in the bottom left picture for now The above supplemental video (Right talar DF and abduction with exaggerated motions) is available under the lower extremity module. Subtalar Joint Osteokinematics: WB (CKC) Pronation (unlocking of the foot) Calcaneal eversion (valgus) Talar adduction Internally rotating talus coupled with IR of tibia & fibular (ankle mortise) Talar PF Anterior/inferior translation Lowers MLA *Ignore the midfoot & forefoot motion in the bottom left picture for now The above supplemental video (Right talar PF and adduction with exaggerated motions) is available under the lower extremity module. STJ Osteokinematics: WB (CKC) - Recap Supination Pronation Frontal plane Calcaneal inversion Calcaneal eversion Transverse plane Talar abduction Talar adduction Sagittal plane Talar DF Talar PF Tibiofular ER IR Video from: https://www.youtube.com/watch?v=0R4zRSE_-40 (Time: 5:49 – 6:57)  Subtalar Joint Summary of Coupled Osteokinematic Motions NWB WB (OKC) (CKC) Supination Calcaneal inversion Calcaneal inversion Calcaneal adduction Talar abduction Calcaneal PF Talar DF Tibiofibular ER Pronation Calcaneal eversion Calcaneal eversion Calcaneal abduction Talar adduction Calcaneal DF Talar PF Tibiofibular IR In the same plane, direction of talar movement in WB is opposite of calcaneal movement in NWB. Does it make sense to you? Subtalar Joint ROM Inversion/eversion Normal ROM 20 deg inversion & 10 deg eversion Functional ROM Normal gait 4 – 6 deg inversion & 4 – 6 deg eversion  Subtalar Joint Arthrokinematics Posterior articulation of STJ Talus PF (posterior facet): concave Calcaneus PF: convex Considering posterior articulation of STJ ONLY Calcaneal inversion at the STJ (OKC & CKC supination) What roll? What slide? Calcaneal eversion at the STJ (OKC & CKC pronation) What roll? What slide?  Subtalar Joint Arthrokinematics Talar abduction and DF (CKC supination) Superior & lateral slide of talus on calcaneus Subtalar Joint Arthrokinematics Talar adduction and PF (CKC pronation) Inferior & medial slide of talus on calcaneus Transverse Tarsal Joint (TTJ) AKA midtarsal joint Talonavicular Joint (TNJ) Resembles a ball-and- socket joint Provides substantial mobility to medial column of foot Spring ligament inferiorly Floor of TNJ Talar “acetabulum” that supports head of talus, TNJ and MLA The supplemental video (Talonavicular joint, convex and concave articular surfaces) is available under the lower extremity module.  Calcaneocuboid Joint (CCJ) Resembles a saddle joint Allows less motion than the TNJ Provides stability to lateral column of foot Lateral fibers of bifurcate ligament forms primary bond between calcaneus & cuboid Long plantar ligament (superficial) & short plantar ligament (deep) Important stabilizers to lateral longitudinal arch Transverse Tarsal Joint Functions Transitional link between rearfoot & forefoot Mechanically linked to STJ Working together with STJ to control most of supination & pronation During WB activities, pronation & supination of midfoot allows foot to adapt to uneven surfaces Transverse Tarsal Joint Osteokinematics 2 axes of rotation Longitudinal Oblique 2 unique planes Supination/pronation ROM: about 2:1 ratio Most WB activities, a blending of movements across both axes  Transverse Tarsal Joint Osteokinematics Longitudinal axis: nearly a straight AP axis of rotation Transverse Tarsal Joint Osteokinematics Oblique axis: Strong vertical & med-lat pitch Combined Action of STJ & TTJ (OKC): Osteokinematics & TNJ Arthrokinematics Active supination of an unloaded foot Supination at both TTJ & STJ Tibialis posterior: prime supinator of the foot At the TTJ, relatively rigid CCJ à pivot point is TNJ Tibialis posterior contributes to the spin of navicular and raising of MLA TNJ: Concave navicular & spring ligament spin around convex talar head (video on the next slide) The supplemental video (Transverse tarsal joint supination) is available under the lower extremity module. Combined Action of STJ & TTJ (OKC): Osteokinematics & TNJ Arthrokinematics Active pronation of an unloaded foot Pronation at both TTJ & STJ Fibularis longus: lowers medial side and raises lateral side of foot TNJ: Concave navicular & spring ligament spin reversely (as compared to supination) around convex talar head (video on the next slide) The supplemental video (Transverse tarsal joint pronation) is available under the lower extremity module. Medial Longitudinal Arch (MLA) of the Foot Primary load-bearing and shock-absorbing structure Bones forming the arch: calcaneus, talus, navicular, cuneiforms and three medial metatarsals Keystone: TNJ Medial Longitudinal Arch (MLA) of the Foot MLA and associated connective tissues are usu. adequate to support the foot during low- stress or near-static conditions, e.g., standing at ease Plantar fascia acts like a semi-elastic tie-rod How does our body respond when the loads are larger and more dynamic? Combined Action of STJ & TTJ (CKC): Osteokinematics during Early to Mid Stance Phase Joint Action Desired Function STJ Pronation & Coupled with IR of leg lowering of MLA Allows foot to function as a shock absorber Produces a pliable midfoot TTJ Relative supination Allows full extent of STJ as a response to pronation counterforce from ground Combined Action of STJ & TTJ (CKC): Osteokinematics during Early to Mid Stance Phase The supplemental video (STJ and TTJ motions during early to mid stance phase) is available under the lower extremity module. Combined Action of STJ & TTJ (CKC): Osteokinematics during Early to Mid Stance Phase Video from: https://www.youtube.com/watch?v=YkNgFQDMJG0 (Time: 1:07 – 2:17) Combined Action of STJ & TTJ (CKC): Osteokinematics during Mid to Late Stance Phase Joint Action Desired Function STJ Changing to Coupled with ER of leg supination, followed Converts midfoot to a rigid by raising of MLA lever for push off TTJ Relative pronation Allows midfoot & forefoot to maintain firm contact with ground Combined Action of STJ & TTJ (CKC): Osteokinematics during Mid to Late Stance Phase The supplemental video (STJ and TTJ motions during mid to late stance phase) is available under the lower extremity module.  Combined Action of STJ & TTJ (CKC): Osteokinematics during Mid to Late Stance Phase Video from: https://www.youtube.com/watch?v=YkNgFQDMJG0 (Time: 2:24 – 4:03)  Distal Intertarsal Joints Three joints or joint complexes in midfoot Cuneonavicular joint Cuboideonavicular joint Intercuneiform and cuneocuboid joint complex Functions Assist TTJ in pronating and supinating the midfoot Provide stability across the midfoot by forming the transverse arch Keystone: intermediate cuneiform Tarsometatarsal Joints Intermetatarsal Joints Least mobility at 2nd and 3rd tarsometatarsal joints Longitudinal stability; useful in late stance 1st tarsometatarsal joint PF with slight eversion DF with slight inversion Are the above movement combinations typical or atypical at the foot? Intermetatarsal joints Their slight motion augments tarsometatarsal joints Metatarsophalangeal Joints (MTP Joints) Metatarsal heads: convex Proximal end of proximal phalanges: concave Two degrees of freedom Sagittal plane Extension (DF) Flexion (PF) Transverse plane (2nd digit as the reference digit) Abduction Adduction PROM 65 degrees extension (except big toe, which has near 85 degrees extension) 30 – 40 degrees flexion Interphalangeal Joints Head of more proximal phalanx: convex Base of more distal phalanx: concave Flexion & extension ONLY ROM: flexion > extension Windlass Effect during Late Stance Phase A primary mechanism used to lift the MLA Full extension of MTPs à Stretches plantar fascia à Raises and stabilizes the MLA à midfoot and forefoot become relatively stable Why is the windlass effect important during the late stance phase? Video from: https://www.youtube.com/watch?v=-UN0CGKLnA4&list=PLtSCIRb9yzwajXE10vtZlxSuC75BKccq3&index=1 Extrinsic Muscles Intrinsic Muscles  Extrinsic Muscle Function Anterior Compartment Pre-tibial Dorsiflexors Swing Phase Lift the foot & toes off the ground to provide adequate clearance Early stance Control the descent of the foot onto the ground (Eccentric) Video from: https://www.youtube.com/watch?v=5j4YRHf6Iyo (Muted on purpose because the narratives are irrelevant. Time: 0:30 – 0:40) Extrinsic Muscle Function Lateral Compartment Fibularis longus and brevis Most active throughout middle and late stance phases of gait Why? Think about the STJ motion during the phases Fibularis longus also helps fixate the first ray securely on the ground  Extrinsic Muscle Function Posterior Compartment (Superficial Muscle Group) Active from the foot flat phase to just before heel off What for? What kind of contraction? Not MCQ; enter your answer When poll is active, respond at PollEV.com/wingfu738 OR text WINGFU738 to 22333 once to join  Extrinsic Muscle Function Posterior Compartment (Superficial Muscle Group) Active between the heel off and toe off phases What for? What kind of contraction? Not MCQ; enter your answer When poll is active, respond at PollEV.com/wingfu738 OR text WINGFU738 to 22333 once to join Extrinsic Muscle Function Posterior Compartment: Deep Group Phase Osteokinematics Role of the at STJ & Change Deep Group in the height of Muscles MLA Early to Mid Stance Mid to Late Stance Reference Neumann DA. Kinesiology of the musculoskeletal system: foundations for rehabilitation. 3rd ed. St. Louis: Elsevier; 2017.